Patina from the historical-artistic point of
view
Phoebe Dent Weil
Northern Light Studio, LLC
This paper reviews the evolving meaning of the term patina and shows how the use of
the word is reflected in changing attitudes towards corrosion, surface coloration of works
of art and conservation treatment of bronze sculpture.
Introduction
Patina is an Italian term that has been freely borrowed into other languages: for
example the German Patina, the French word patine, and the English form where
it is written patina, but typically pronounced pa-ti’-na. Its current usage is, as it
has been from its earliest traceable meaning, broad and inclusive rather than
narrowly scientific and precise. It can refer in the, widest sense to the effects of
time, weathering, accumulation of particulate matter, corrosion and use, and
normally implies a positive or desirable aspect of these changes. For the
conservation of works of art, and here, for our discussion of the conservation of
outdoor bronze sculpture, the notion of patina in its broadest sense presents a
problem, the irony of which should be immediately apparent: if the goal of
conservation is to prevent change, to determine the causes and effects of
change, and to counteract those changes, when, if ever, can patina be
considered valuable? Is there such a thing as “good patina”? What are the
aesthetic requirements for judging a good patina as distinguished from one that
is deleterious? Or, in reference to the special case of sculpture, how have
sculptors dealt with the problem of form in relation to color?i
The case of patina as the word has been used in reference to outdoor bronze
sculpture has presented specific and complex problems for interpretation and
preservation from antiquity to the present day.ii Part of the problem lies in the
high reactivity of the freshly exposed copper alloy surface which, even in indoor
conditions, quickly alters, acquiring a tarnish and is highly vulnerable to staining
and discoloration in contact with airborne pollutants, and especially to water or
other liquids. The artistic process of the sculptor and also the aesthetic
enjoyment of looking at sculpture has always necessarily included some form of
surface treatment to enhance and complement visual reading of the forms, and
also necessarily to perform the task of stabilization and protection of the
vulnerable raw bronze surface, the latter function being particularly significant for
bronzes under aggressive outdoor conditions where random discoloration of the
surfaces typically disfigure and interfere with the visual reading of the sculptural
forms and surface textures. Significantly, the discolorations represent the
formation of corrosion products that are formed at the expense of the underlying
metal and represent an irreversible physical loss.
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Patina in Antiquity
The peculiar characteristic of bronze to form a wide range of colored corrosion
products early on inspired wonder and curiosity in manipulating the metal
exposing it to different reagents and exploring potential uses for the results, most
of which were medicinal or cosmetic, and which had the effect ultimately of
stimulating the development of the field of chemistry. iii Cyril Smith has cited this
development as a good example of scientific discovery motivated by aesthetic
curiosity,iv and Forbes has pointed out the origin of the word “chemistry” is found
in the ancient Greek chyma meaning “casting”.v
In the ancient world prevailing aesthetic notions regarding surface coloration and
strategy for protection of surfaces of bronze sculpture were quite different from
what they are today. Because the surfaces of all ancient bronzes, with few
exceptions, have corroded and altered under conditions of burial, submersion in
sea water, or outdoor exposure, there are almost none that provide us with a well
preserved indication of their original appearance. The typical azurite and
malachite corrosion that has formed on these bronzes can be immensely
appealing in color which has been admired as a thing of beauty in itself having
been formed over a long period of time and as a result of natural processes
outside and beyond the intentions of the original fabricator. Early speculation
about these pieces included the possibility that the green or blue appearance
might have been intentional. As more ancient bronzes have been discovered
and carefully studied, the physical evidence together with interpretation of the
written documentation have become increasingly persuasive that ancient bronze
sculpture was polished and the gleaming golden surfaces were adorned with
inlays for both ornamentation and naturalistic coloration effects produced from a
variety of materials.vi These might include reddish copper, for example, to
represent lips, nipples, and blood, silver for teeth, alloys of other colors and a
variety of materials such as colored stone for representing the whites and colored
iris and pupil of the eye, and dark black niello. That examples of varieties in
approaches to coloration was richer than imagined has been demonstrated by
Giumlia-Mair and Lehr in their investigations of black patina on ancient bronzes,vii
and studies of the polychromy of Egyptian bronzes are only beginning. The
protection and maintenance of ancient polished metal sculpture was dependent
on a protective coating of bitumen or pine-tar pitch that both provided an overall
unifying warm coloration to the surfaces and protected them from disfiguration
and discoloration.viii
Such a coating required maintenance in order to remain effective and records
exist of payments for removing and renewing the pitch coating and repolishing
the metal surface.ix Erich Pernice seems to have been the first to attempt a
reconstruction of the ancient practice of applying bitumen to a polished bronze
surfacex I have also applied a pitch coating to 85-5-5-5 bronze to observe the
effect on the polished surface which is that of a translucent warm glaze, the color
of glowing tanned skin.
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It is worth noting here that protective coatings were applied not only to bronze
sculpture but also on marble sculpture which was typically enhanced with painted
polychromy. Vitruvius describes the wax coating used to protect the surfaces of
marble sculpture.xi
This coating was also removed and renewed as a
maintenance practice. Pliny, the notable first century C.E. Roman author of the
encyclopedic Natural History, made observations that have been frequently
quoted, both about the corrosion of copper and also about the application of a
protective coating on bronze sculpture.xii He uses the terms aerugo, aeruginis,
to denote the “rust” (robigine) of bronze (aes), and describes various methods of
producing it artificially for medical and cosmetic purposes but not for the
coloration of bronze sculpture. Pliny also makes a distinction between two kinds
of aerugo: one which is attractive, enhancing and stable (aerugo nobilis, or noble
patina) and another which is unattractive, disfiguring and destructive, or virus
aerugo which has been translated “vile” or rather “virulent”. Regarding the
application of a protective coating on bronze, Pliny states that the ancients
painted their statues with a coating of bitumen, and further, that it was surprising
that later the Romans began gilding outdoor sculpture. The surprise seems to
have been due to the fact that a polished and bitumen-coated sculpture had the
appearance of gold and therefore the extra expense and effort of gilding was
unnecessary. Gilding, while lavishly expensive and dangerous to the artisan
gilder, would, however, have been a more durable surface treatment and require
less maintenance, and a number of Roman bronzes with remains of gilding have
survived, such as the Marcus Aurelius and the bronze horses of San Marco.xiii
The Middle Ages
Of the few documentary sources that have come down to us, an inscription of
1076 A.D. on the bronze doors of the church of S. Michele at Monte S. Angelo
instructs those in charge to clean the doors once a year so that they will always
be shiny and bright.xiv Large-scale outdoor bronze sculpture was not being
produced, but smaller scale bronzes and brasses were typically polished and
occasionally inlaid with precious stones, gilded or polycrhomed with enamel. The
early 9th century Mappae Clavicula describes the artificial production of corrosion
products on copper using vinegar and other reagents to be used for pigments,
cosmetics and various medicinal purposes but does not include coloration of
bronze sculpture.xv Theophilus’ De diversis artibusxvi, describes a method of
producing an overall, even brownish coating on bronze or copper objects by
means of linseed oil and heat. However whether or not this finish was used for
sculpture is not certain.
The Renaissance
The return of large-scale bronze statuary in the Renaissance introduced a rebirth
of bronze casting technology as well as a renewed interest in the artistic
achievements of the ancient world. Donatello’s David, c. 1430, was the first
ambitious free-standing full length bronze figure cast since antiquity. Because
casting technology had not sufficiently developed , the early Florentine bronzes
were typically full of casting flaws and therefore required a dark varnish that was
4
more or less opaque. Coloristic effects could be achieved by picking out details
in gilding, or as in Donatello’s St. Louis of Toulouse, on an even grander scale
than the David, the piece could be cast in parts, each of which were gilded and
assembled to produce a large-scale gilded bronze. The exquisite surfaces and
skilled chasing with touches of parcel gilding on later bronzes, for example
Verrocchio’s Christ and St. Thomas and Benvenuto Cellini’s Perseus have been
revealed by conservation treatments in recent years. Both sculptures have
remnants of gilded details, so the original coloration was most likely a dark or
brownish resin or by application of a resin or oil with heat. Pomponius Gauricus
in his De Sculptura of 1504, provides us with the first modern account of surface
treatments for bronze sculpture based on his observations in the bronze
foundries in Padua: “All beauty,” he says, “ appears perfect in the polishing and
coloration. In the polishing we remove all harshness of the filing by means of a
scraper, and we add the shine with pumice or with a point or with a burnisher.
For coloration we give the color to each part whether in the cast itself (i.e. by
alloying) or, he goes on to describe the following colors: “white is achieved by
the application of silver leaf, yellow, i.e. gold, with gold leaf, green by wetting with
salted vinegar, and black by a varnish of liquid pitch or smoke of wet straw.
These colors will do for now, in waiting for the time that we will learn others.”xvii I
know of no existing green coloration on a Renaissance bronze, but color applied
‘to each part” appears to indicate touches of polychromy of details produced by
application of gold or silver rather than an overall coloration.
The preface of Giorgio Vasari’s Vite (1550-1568) simply states that bronze,
“assumes through time and by natural change a color that draws toward
black…Some turn it black with oil, and others with vinegar make it green, and
others with varnish give it the color of black so that everyone makes it come as
he likes best.”xviii
The most popular and most common finish for bronze
sculpture large and small seems to have been a dark lacquer that may have
been the result of a misinterpretation of Pliny’s mention of a bituminous coating
which was presumed to have been dark and semi-opaque rather than a
translucent warm glaze. An opaque coating would serve the purpose of
providing visual uniformity by concealing casting flaws and repairs. As casting
technology became more sophisticated the exquisite finish and chasing of late
16th century works, for example, by Giambologna and the Susini workshop,
translucent reddish lacquers of exquisite beauty were employed producing the
prized effect of polished metal viewed through a dark, red-brown, glossy varnish.
For works on a larger scale either a dark varnish or simple heating over a smoky
straw fire and rubbing with oil served to produce a uniform lustrous and
translucent brown of copper oxide.
The account by André Felibien in his Principes of 1699 provides the only account
for patination in the 17th century that I have been able to locate: “After [the
bronzes] have been well cleaned and repaired, one gives them if one wishes, a
color. There are those who use for that purpose oil and sanguine (red earth
5
pigment), others make it become green with vinegar. But with time bronze takes
on a varnish which tends toward black.”xix
From patena to patina: 18th and 19th c. developments
Perhaps the most surprising discovery in my initial exploration of the history of
the coloration of bronze sculpture, was that the word patina was first used not in
reference to the coloration of bronze but in reference to the effects of age and
discolored varnish on paintings and only towards the middle of the 18 th century
came to be applied to corrosion crusts found on antique bronze sculpture and
artifacts. The first printed definition of the word is in a variant form, patena, that
can be found in Filippo Baldinucci’s Vocabolario Toscano dell’ Arte del Disegno
published in Florence in 1681. Baldinucci defines patena as follows: “…a term
used by painters, called by others a skin (pelle), namely that general, dark tone
which time causes to appear on paintings, that can occasionally be flattering to
them.”xx Patena is an old Italian word used to refer to a shiny dark varnish
applied to shoes,xxi and whose meaning was easily understood as a description
of the darkened varnish on painting.
It was not until the mid-18th century that the word appears in a dictionary where it
refers to green corrosion products found on bronze artifacts. Patine is defined in
the French Encyclopedie of 1751 as follows: “There is no French word to express
that beautiful and brilliant color of verdigris that copper does not always assume;
the attractiveness of this color to the eye and the difficulty in describing it
(because all coppers do not uniformly develop it) is highly valued by the Italians
who call it patina as one dares to do here after their example and by the example
of M. le Comte de Caylus who states correctly that one should be allowed to
adopt a foreign word at least in the language of the arts of which this
Encyclopedia is the Dictionary”.”xxii
The Encyclopédie also provides information about artificial patination under the
entry on sculpture: “ As to the pitch with which the ancients covered their
bronzes, we have no desire for it; the smoke and preparations of our artists are
far preferable, because they have less thickness.”xxiii
The philological aspects of the word appear to reflect the historical situation:
while coloristic effects were achieved in bronze sculpture by a variety of means
from earliest times, it was not until the 18th century and the new enthusiasm for
archeological bronzes that green corrosion products began to be appreciated
and valued in themselves. According to the Oxford English Dictionary, the
earliest recorded English usage of patina describing green corrosion products on
bronze as late as 1797. According to the Italian etymological dictionaries, the
Italian verbs meaning to give a patina, patinated, and patinator are all 19th
century in origin.xxiv It was not until the late 19th century that artificial patination of
bronzes by chemical means, with or without heat, was generally and widely
practiced.
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19th century developments: the industrial age
It is hard for us living in the 20th century to imagine many aspects of life in the
pre-industrial world. No one living today can remember a time before the
invisible invasion of sulfur-polluted air produced the slow and subtle changes in
the appearance of outdoor urban bronzes from brown lustrous oxide or dark
lacquer to a general overall opaque, matte, black or pale green. It is not
surprising, then, that in most cities, where most outdoor bronzes have been
placed, and where sulfur pollution has been the greatest, that a green
appearance came to be accepted as the expected norm, and was described as
“natural patina” and desirable when in fact it was the result of un-natural causes.
Further, since “natural” was equated with “good” and “desirable” no one thought
to look closely at the surfaces of these monuments to discover the truth that their
surfaces were being progressively destroyed physically and irretrievably and their
artistic and visual message was being altered and distorted. Throughout my
conservation training that began in the late 1950’s, outdoor sculpture was never
mentioned as a conservation problem. It became a great irony that the most
highly visible, and in many cases, the most sizeable works of art were being
destroyed and the damage was only recognized after it was too late. It was only
in the early 1970’s when the gilded ancient bronze horses on the façade of the
basilica of San Marco were studied closely that the conservation world began to
be awakened to the vulnerability of bronzes exposed to the polluted atmosphere
of the modern world, and to face the complex problems of treatment for works of
art already irreparably damaged.
At the ICOM-CC meetings in Madrid in 1972 the first presentations were made
revealing the severity of corrosive attack on outdoor bronze sculpture. Joseph
Riederer’s detailed photographs of the surfaces of outdoor bronze sculpture in
Munich encouraged observations in other parts of the world where similar serious
corrosion was observed and a previously ignored conservation problem began to
be recognized. The conservation community first turned to conservators of
archaeological metals who could identify corrosion products, typically called
“patina”, who could, like John Gettens, distinguish between what was termed
“noble” and “vile” patina, and could execute appropriate and ethical treatments.
However applying these criteria to outdoor bronze sculpture was problematic:
The corrosion products on outdoor bronzes were altogether different from those
that had been produced under burial conditions, basic copper carbonates in the
form of azurite and malachite predominating in the former with instances of
copper chlorides representing vile patina; and brochantite or basic copper sulfate
predominating on the latter. The presumption that the green brochantite patina
on outdoor bronzes, widely promulgated in the literature of corrosion science as
not only protective but attractive and “natural”, was proven false.
The expanding demand for outdoor bronze sculpture in the 19 th century was met
by developing technology particularly in Germany where the emergence of
industry and science combined to make large scale production of sculpture
possible and also the industrial development that introduced large quantities of
7
sulfur into the atmosphere as well as the scientific development in chemistry
which enabled scientists to detect the cause of changes in the appearance of
outdoor bronzes in Berlin in the 1860’s.
The Royal Foundry in Munich directed by Ferdinand von Miller was the preeminent foundry in Europe for bronze sculpture on a large scale from the 1830’s
up until the 1880’s having produced the colossal 18 meter high cast of
Schwanthaler’s Bavaria between 1837-48. Von Miller used a sand casting
technique producing bronze casts of extremely high quality and with an alloy in
which he took particular pride. Von Miller used an alloy intentionally selected to
give “luster and malleability” and “to prevent the statues from turning green by
years of exposure.” Von Miller’s letters preserved in the Valentine Museum in
Richmond, Virginia, provide specific instructions for maintenance of the
Washington Monument bronzes cast in Munich between 1849-69, as well as his
stated desire regarding the appearance of the bronzes. Maintenance was
important, “for the color of the metal imparts a peculiar beauty to works of art.”
The fame of von Miller’s “gold bronze” was widespread by the 1870’s, according
to an article in the New York Tribune in 1874, in which it was compared with the
predominantly brown tones of contemporary bronzes from other foundries.xxv
The Munich foundry of von Miller was overtaken by the exceptional development
of French foundries in the 1880’s to meet the enormous new demand for outdoor
monuments, and the re-discovery of lost wax casting to meet this demand. Cire
perdue casting, which has dominated fine arts casting ever since, presents
numerous artistic advantages for sculptors. Editions of a work can be produced
with relative ease, and surfaces and textures, even with detailed undercuts can
be reproduced with exceptional precision and with minimal need for chasing and
mechanical reworking. Along with the expansive development of lost wax
casting in France in the latter part of the 19 th century to meet the increasing
demand for outdoor bronze monuments came the development of artificial
chemical patination as a specialized art. The master patineurs took over the
coloration of bronzes in the foundry and those, such as the Limet brothers, not
only acquired great fame in their own right in producing patinas but also served
as consultants on coloration for artists such as Rodin. Artists themselves
became increasingly interested in the possibilities of coloration and the more
aware were also disturbed by the effects that they came to observe on
deteriorating surfaces of sculpture exposed to polluted urban air.
Augustus Saint-Gaudens, the American sculptor who studied in Paris in the latter
part of the 19th century and was intensely preoccupied with the patination and
finishing of his bronzes, had his large equestrian monument of General Sherman
gilded at his own expense because he feared that his sculptures woud end up
“looking like old stove pipes.”xxvi
The earliest descriptions of undesirable changes in the appearance of outdoor
bronze sculpture, as well as documentation of scientific research into the cause
8
for the changes were provided by Magnus in the 1860’s and the reports of the
activity of the Berlin Patina Commission.xxvii This work, continued by Puscher,xxviii
Donathxxix and Vanino and Seitterxxx, and Hiorns, whose important study
appeared in 1892 in Londonxxxi began the development of the patina literature
with “patina” being equated with corrosion products on bronze sculpture, and
making the careful distinction between patina that is “natural” and patina that is
“artificial” as well as, following Pliny’s distinction, patina that is “noble” or “vile”.
Causes for undesirable change in appearance on outdoor sculpture were
recognized as resulting from gaseous sulfur compounds released by industrial
activity and methods of producing a controlled and desirable variety of colored
patinas on bronze surfaces was explored.xxxii The rich information contained in
these early studies have been largely ignored in the later literature and the alarm
sounded for the need to protect outdoor bronze sculpture in urban environments
went unheeded and then forgotten with the intervening historical events of two
World Wars.
Some of the most interesting passages from these early writers are to be found
in passages describing what they consider to be desirable aspects of a “noble”
patina whether “natural” or “artificial”. Hiorns admires what he describes as the
effects of “Nature” on metals, and states that it is desirable to attempt to imitate
those effects in producing an artificial patina with the important condition:
“…always provided that the colours aimed at are strictly in keeping with the
metallic character.”xxxiii Elsewhere he states, “a metallic article is not like a
canvas or paper, which has to be completely covered with paint of all
colours…but a material which must always assert its peculiar metallic character,
so that there is never any doubt as to its real nature.”xxxiv The question of
distinguishing “noble” from “vile” appears in the earliest bronze conservation
literature published by Friedrich Rathgen, founder of the first museum scientific
laboratory in Berlin in the 1890’s concerned primarily with archeological
bronzes.xxxv This theme is again taken up by Gettens in a paper, “Patina Noble
and Vile” presented to the symposium, “Art and Technology”, sponsored jointly
by Harvard University and M.I.T. in connection with a major exhibition of ancient
bronze artifacts.xxxvi
It should be obvious that the distinctions “natural” and “artificial” and “noble” and
“vile” or “virulent” become particularly important where conservation is concerned
and these categories are different for archeological bronzes and for outdoor
bronze sculpture. Where they have come to be fairly well defined for
archaeological metals they are still problematic for bronze sculpture which
presents a host of very different considerations not all of which can be solved
with the precision of scientific inquiry and clear-cut results. Many outdoor
bronzes have been treated since the early 1970’s including the most important
bronzes in Western art and all of these treatments have had to struggle with the
complexities of large scale, future maintenance, effectiveness and durability
outdoors, surface treatment, and aesthetic appearance. Further, nearly all of
them result in a change of appearance requiring justification from an ethical and
9
aesthetic point of view. Such changes have resulted in bitter disputes, among
the earliest of which was described in a book published in 1888 entitled, Der
Patinakrieg: der Restaurirung des Maxdenkmals zu Innsbruck und der Streit für
und wider dieselbe,xxxvii “The Patina War: the Restoration of the Maximillian
monument in Innsbruck and the struggle for and against it”.
Patina on outdoor bronzes has in every case required intelligent and ethical
consideration involving consideration of wide and diverse aspects of knowledge
both scientific and humanistic. Unlike discolored varnish on a painting, it is
formed from the substance of the metal itself and its presence represents loss of
original surface. The identification of patina on outdoor copper and copper alloys
by Vernon and Whitby in 1929 from studies on copper roofsxxxviii made the clear
distinction between patinas formed in the open air identified as primarily basic
copper sulfate, brochantite, and the patinas formed under burial conditions which
were primarily the copper carbonates, malachite and azurite. The conclusions of
Vernon and Whitby, though impressive from the scientific point of view were
tragically misleading insofar as bronze sculpture was concerned.
Their
statement that the green patina that formed on outdoor bronzes was “natural”,
“protective” and “aesthetically pleasing” contributed to what could be described
as a “blind spot” where outdoor bronzes were ignored insofar as conservation
was concerned.
Studies on the San Marco Horses in Venice followed by the investigations of
Riedererxxxix and Lehmanxl reported on at the 1972 meetings of the ICOM-CC
meetings are landmark investigations demonstrating that patinas, now called
“corrosion damage” and “corrosion” to emphasize that they are not benign, could
not be described as “natural”—they are formed by man-made pollution—nor
“protective” –they promote rather than retard surface deterioration—nor could
they be in any way be described as “aesthetically pleasing”—as they form
randomly colored, speckled and streaked surfaces that serve as camouflage to
the sculptural forms. The work of Weil, et. al., further strengthened and
elaborated these conclusions.xli
Two recent studies demonstrate interesting approaches to the study of patina
presented at a conference held at the Tate Gallery in September of 1995.
Binnie, describes a technique of color monitoring on outdoor bronze sculpture in
Ottawaxlii, and Summers presents the problems of patina in two identical bronzes
by Henry Moore.xliii
Contact information
Phoebe Dent Weil
Northern Light Studio, LLC
1602 Locust Street / Suite 815
St. Louis, MO 63103
USA
10
Fax: +1 314-588-9681
e-mail: phoebe@northernlightstudio.com
References and notes
i
For a discussion of specific problems of the evolving notions of the relationship of color
and form see Weil, P., Patina: Historical Perspective on Artistic Intent and Subsequent
Effects of Time, Nature, and Man, in Naudé, V., (ed.), Sculptural Monuments in an
Outdoor Environment, Philadelphia, PENNSYLVANIA ACADEMY OF THE FINE
ARTS, 1985, pp. 21-22.
ii
I have discussed patina, the history of the meaning and use of the word, its evolving
aesthetic perspective and the practice of artificial patination in two previous articles, the
first: Weil, P.,“A Review of the History and Practice of Patination”, in Brown, B.,
Burnett, H. et.al. (eds), Corrosion and Metal Artifacts, National Bureau of Standards
Special Publication 479, Washington, DC: US GOVERNMENT PRINTING OFFICE,
1977, pp. 77-92, reprinted in Price, N., Talley, M. , and Vaccaro, A., (eds.), Historical
and Philosophical Issues in the Conservation of Cultural Heritage, Los Angeles THE
GETTY CONSERVATION INSTITUTE, 1995, pp. 394-414. NOTE: the following
errata in the Getty reprint: p. 394: should read “virus aerugo”; and on p. 404, bottom of
the page, should read “largely” instead of “little”. The second article is Weil, P.,
Patina: Historical Perspective on Artistic Intent and Subsequent Effects of time, Nature
and Man, in Naudé, V., (ed.), Sculptural Monuments in an Outdoor Environment,
Philadelphia, PENNSYLVANIA ACADEMY OF THE FINE ARTS, 1985, pp. 21-27.
iii
See, e.g., Smith, C.S., A History of Metallography, 2nd ed., Chicago, 1965, p. 2;
Partington, J.R., Origins and Development of applied Chemistry, London, 1935;
Hopkins, A.J., Alchemy, Child of Greek Philosophy, N.Y., 1934.
iv
Smith, C., Materials and the Development of Civilization and Science, in Science, 148,
April-June 1965, p. 908.
v
Forbes, E., The Origins of Alchemy, in Studies in Ancient Technology I, 2nd ed., Leiden,
1964.
vi
Weil, P. (1977), pp. 81-83; Weil, P., (1985) pp. 24-25. Further, see the following
articles in La Niece, S., and Craddock, P. (eds), Metal Plating and Patination: cultural
and Historical Developments, Oxford, BUTTERWORTH-HEINEMANN, LTD., 1993:
Hughes, R., Artificial Patination, p. 6; Born, H., Multi-Colored Antique Bronze Statues,
p. 19; Craddock, P. and Giumlia-Mair, A., Beauty if Skin Deep: Evidence of the Original
Appearance of Classical Statuary, p. 30; as well as Mattusch, C., Classical Bronzes,
Ithaca and London, CORNELL UNIVERSITY PRESS, 1996, pp. 24, 26, 29; Mattusch,
C., Greek Bronze Statuary, Ithaca and London, CORNELL UNIVERSITY PRESS,
1988, pp. 98.ff.
vii
Giumlia-Mair, A. and Lehr, M., Patinating Black Bronzes: Texts and Tests, in
Proceedings of the Fourth International Conference on the Beginning of the Use on
Metals and Alloys (BUMA-IV), May 25-27, 1998, Kunibiki Messe, Matsue, Shimane,
Japan, The Japan Institute of Metals.
11
viii
Weil, P., (1977), p. 82; Weil, P., (1985), p.25. Further see the discussions regarding
the black coating on the Riace bronzes in Born, H., op. cit. p.24.; Craddock, P. and
Giumlia-Mair, A., op. cit., p. 30.; Scott, D., Copper and Bronze in Art, Los Angeles,
GETTY PUBLICATIONS, 2002, pp. 328-329.
ix
Pernice, E., Untersuchungen zur antiken Toreutik, V. Natürliche und Künstliche Patina
im Altertum, in Jahreshefte des Osterreichischen Archäologischen Institutes in Wien,
XIII, 1910, pp. 102-107.
x
Pernice, E., op. cit.
xi
Vitruvius, On Architecture, 2 vols., Granger, F. (ed), Loeb Library, Cambridge, MA,
HARVARD UNIVERSITY PRESS, 1970, vol. II, p. 119 (VII.ix. 3); Reuterswärd,
Studien zur Polychromie der Plastik Griechenland und Rom, Stockholm, 1960; Cagiano
de Azevedo, M., Conservazione e restauro presso I Greci e I Romani, Bollettino dell’
Istituto Centrale del Restauro, 9-10, 1952, pp.53-60.
xii
Pliny, Natural History, 10 vols, Loeb Library, vol. IX, Rackham, H. tr., London, 1968,
XXXIV.
xiii
Weil, P. (1977), pp. 82-83.
xiv
Federici, V. Le Porte Bizantine di San Marco, Venice, STADIUM CATTOLICO
VENEZIANO, 1969.
xv
Smith, C. and Hawthorne, J., Mappae Clavicula: A Little Key to Medieval Techniques,
Philadelphia, 1974.
xvi
Theophilus, De diversis artibus, (1110-40) London, Dodwell, C.R., ed., THOMAS
NELSON, 1961.
xvii
Pomponius Gauricus, De Sculptura, 1504, p. 239.
xviii
Vasari, G. Le Vite…, 1550, 1568, Milanesi, G., ed., Florence 1878; “Prefix” to the
Vite, tr. And ed. Maclehose and Brown, Vasari on Technique, N.Y., 1960, pp. 165-166.;
Bettarini, R. and Barocchi, P., eds, Verona, 1966, vol. I, p. 103. The quote reads:
“Questo bronzo piglia col tempo per se medesimo un colore che trae in nero e non in
rosso come quando si lavora. Alcuni con olio lo fanno venire nero, altri con l’aceto lo
fanno verde, et altri con la vernice li dànno il colore di nero, tale che ognuno lo conduce
come più gli piace. Nel che si vede questa arte essere in maggior eccellenza che non era
al tempo degli antichi.”
xix
Félibien, A., Des Principes de l’Architecture, de la Sculpture, de la Peinture, et des
autres Arts qui en dependent, Paris, 1699, Farnborough, Hants., England, 1966, p.239.
“Après qu’elles sont bien nettoyées & reparées, on leur donne si l’on veut une couleur. Il
y en a qui prennent pour cela de l’Huile & de la Sanguine; d’autres les font devenir
vertes avec du Vinaigre. Mais avec le temps la bronze prend un vernis qui tire sur le
noir”
xx
Baldinucci, F., Vocabolario Toscano dell’Arte del Disegno, Florence, 1681. “
”Patena, voce usata da’ Pittori, e diconla altrimenti Pelle, ed è quella universale scurit~a
che il tempo fa apparire sopra le pitture, che anche talvolta le favorisce.”
xxi
Battisti and Alessio, Dizionario Etimologico Italiano, Florence, 1954. (patina)
The Cambridge Italian Dictionary, vol. I, Reynolds, B. (ed.) , Cambridge, 1962. (patina)
xxii
Diderot and d’Alembert, Encyclopédie ou dictionnaire raisonnedes sciences, des arts
et des métiers, par une societe de gens de letters, Neufchastel, 1765; Lausanne, 1780-82.
12
“Patine: Il n’y a point de mot francois pour exprimer cette belle & brilliante couleur de
vert-de-gris que le cuivre ne prend pas toujours; l’agrément de cette couleur pour l’oeil
& la difficulté de la renconter (car tous les cuivres ne s’en chargent pas également), la
rendent trés-recommandable aux Italiens, qui la nomment patina , comme on ose ici le
faire d’après eux, & par l’example de M. le comte de Caylus, Il doit etre permis, dit-il
avec raison, d’adopter un mot étranger au moins dans la langue des arts,”
xxiii
Diderot, Encyclopédie, op. cit., “Quant à la poix dont les anciens couvroient leurs
bronzes, nous n’avons rien à desirer; les fumes & les preparations de nos artistes sont
d’autant préferables, qu’elles ont moins d’épaisseur.”
xxiv
Battisti and Alessio, op. cit.
xxv
Cook, C., Palmer’s Statue of Livingstone in New York Tribune, July 8, 1874, pp. 4-5.
xxvi
Dryfhout, J., Augustus Saint-Gaudens, in Wasserman, J., (ed.) Metamorphoses in
Nineteenth-Century Sculpture, Cambridge, MA, HARVARD UNIVERSITY PRESS,
1975, p. 183.
xxvii
Magnus, G., Uber die Einfluss der Bronzezusammensetzung auf die Erzeugung der
schönen grunen Patina, in Dinglers Polytechnisches Journal, 172,1864, pp. 370-376.
Further, see articles listed in the bibliography published by S. Lewin and S. Alexander,
The Composition and Structure of Natural Patinas, Part I, Copper and Copper Alloys,
Section A, Antiquity to 1929; Section “B, 1930 to 1967, Art and Archaeology Technical
Abstracts, VI, 4, 1967; and VII, 1, 1968. Also references in P. Weil (1977), p. 91, note
51.
xxviii
Puscher, C. Artificial patinas, in Polytechnisches Notizblatt, 38,90, 1883.
xxix
Donath, E., Artificial patination, in Dinglers Polytechnisches Journal, 253, 376-80,
1884.
xxx
Vanino, L, and Seitter, E., Patina. Its Natural and Artificial Formation on Copper and
its Alloys, Vienna, 1903.
xxxi
Hiorns, A., Metal-Colouring and Bronzing, 2nd ed., London, 1911.
xxxii
The rich literature on artificial patination has been outlined in Weil, P. (1977), pp. 9192, Recent contributions include Hughes, R., and Rowe, M., The Coloring, Bronzing
and Patination of Metals: A Manual for the Fine Metal Worker and Sculptor, London
CRAFTS COUNCIL, 1982; and Hughes, R., Artificial Patination in La Niece, S., and
Craddock, P., Metal Plating and Patination, Oxford, BUTTERWORTH-HEINEMAN,
1993, pp. 1-18
xxxiii
Hiorns, A., op. cit., p. 5.
xxxiv
Hiorns, A., op. cit., p. 67.
xxxv
Rathgen, F., The Preservation of Antiquities, Cambridge, 1905, pp. 34-36.
xxxvi
Gettens, J., Patina Noble and Vile, in Doeringer, S., Mitten, D., Steinberg, A., Art
and Technology, Cambridge, MIT PRESS, 1970, pp. 57-68.
xxxvii
Der Patinakrieg: die Restaurirung des Maxdenkmals zu Innsbruck und der Streit für
und wider dieselbe, Innsbruck, Wagnerschen Universitaets-Buchhandlung, 1883.
xxxviii
Vernon, W, and Whitby, L., The Open-Air Corrosion of Copper: A Chemical Study
of the Surface Patina, in Journal of the Institute of Metals, 42 (1929), pp. 181-95 (Part I)
44 (1930) p. 389-96 (part II; 49 (1932)153-61 (Part III).
xxxix
Riederer, J., Corrosion Damage on Bronze Sculptures, preprint of paper presented to
ICOM Committee for Conservation, Madrid, October 1972,
13
xl
Lehmann, J., Corrosion of Monuments and Antiquities made of Copper and Copper
Alloy in Outdoor Exhibits, preprint of paper presented to ICOM Committee for
Conservation, Madrid, October 1972.
xli
Weil, P., et.al., The Corrosive Deterioration of Outdoor Bronze Sculpture, in Preprints
of the Contributions to the Washington Congress, 3-9 September 1982: Science and
Technology in the Service of Conservation, London, INTERNATIONAL INSTITUTE
FOR CONSERVATION, 1982, pp.130-34.
xlii
Binnie, N., Colour Monitoring on Outdoor Bronze Statues in Ottawa, Canada, in
Heuman, J., (ed.), Marble to Chocolate: the Conservation of Modern Sculpture, Tate
Gallery Conference 18-20 September, 1995, London, ARCHETYPE, 1995, pp. 73-81.
xliii
Summers, Jl, Gilding the Lily: the Patination of Henry Moore’s Bronze Sculpture, in
Heuman, J., (ed.), op. cit., pp. 144-151.